1. Field of the Invention
The present invention relates, in general, to a method of producing BGA (ball grid array) semiconductor packages and to a BGA package produced through such a method and, more particularly, to an improvement in such a method for producing BGA packages, with improved quality, improved heat dissipating effect and reduced manufacturing cost, by forming a strip or reel-type metal carrier frame by attaching a plurality of unit PCBs (printed circuit boards) to individual PCB carriers of a metal carrier frame and by using a part of such a metal carrier frame as heat spreaders of individual resulting BGA packages.
2. Description of the Prior Art
FIGS. 1A and 1B show the construction of a typical BGA (ball grid array) semiconductor package. As shown in the drawings, the typical BGA package comprises a PCB (printed circuit board) 1 and a semiconductor chip 2 attached to the top of the PCB 1. The chip pads of the semiconductor chip 2 are electrically connected to the circuit pattern 11 of the PCB 1 through a plurality of wires 3. The semiconductor chip 2, which is attached to the top of the PCB 1, is packaged with a mold compound 4 thus being prevented from being brought into contact with atmosphere and being prevented from oxidation or corrosion.
In the prior art, such BGA packages are produced using a PCB strip, which includes a plurality of PCBs integrated into a single strip and having individual circuit patterns 11. However, such a method of producing the BGA packages using such a PCB strip is problematic in that the method causes waste of an expensive PCB and thereby increases the manufacturing cost of the BGA packages.
That is, the typical method of producing such BGA packages uses a PCB strip, which includes a plurality of PCBs 1 integrated into a single strip, in an effort to smoothly feed the PCBs and to effectively control the positions of PCBs. However, after producing the BGA packages, it is necessary to cut the PCB strip into individual PCBs, with PCB margins being cut out and discarded thus increasing the manufacturing cost of the packages.
In addition, the PCBs 1 used in the typical BGA packages is made of resin, so that the PCBs 1 may be deformed due to thermal expansion while they are treated in repeated high temperature steps of a package producing process. Such thermally-deformed PCBs cause problems during continued steps of the package producing process.
In the typical BGA package, a plurality of solder balls 5 formed on the PCB 1 are used as signal input and output terminals of the package. When the tips of the solder balls 5 are not leveled on the same plane thus failing to maintain the flatness, the package has some open solder balls when the package is mounted to a mother board. In this case, the BGA package cannot perform its function. When the PCBs 1 are thermally deformed or bent while they are treated in the repeated high temperature steps as described above, the solder balls 5 on each PCB 1 inevitably fails to maintain the flatness, so that such solder balls 5 reduce the quality of a resulting package and thereby reducing productivity and operational reliability of the BGA packages.